Google's Chrome team has unveiled a new security proposal that would fundamentally change how websites interact with devices on your local network. Currently, any website you visit can silently probe your home router, printer, or other connected devices without your knowledge. This proposal aims to put that power back in users' hands through a permission-based system.
The timing of this proposal reflects growing concerns about privacy and security in an increasingly connected world. With more smart devices in homes and the rise of remote work, the potential for abuse has grown significantly. The Chrome team specifically mentions how malicious websites can use your browser as a controlled deputy to attack vulnerable devices on your local network.
The Current Security Gap
Right now, websites can freely send requests to any device on your local network without asking permission. While CORS (Cross-Origin Resource Sharing) provides some protection by limiting what responses websites can read, it doesn't prevent the requests from being sent in the first place. This means a malicious website could potentially exploit vulnerable routers, printers, or other devices by sending specially crafted requests, even if it can't see the responses.
The community has expressed strong support for addressing this security gap. Many users were surprised to learn that websites have this capability at all, with some comparing it to allowing websites to access your entire filesystem - something that would be considered an obvious security flaw.
How the New System Would Work
Under the proposed system, when a website tries to access a device on your local network, your browser would display a permission prompt asking if you want to allow the connection. This applies to requests crossing address space boundaries - essentially when a public website tries to talk to private network devices or localhost services.
The proposal defines three address spaces: public (accessible to anyone), local (your home network), and localhost (only your computer). Requests from more public spaces to more private ones would trigger the permission system.
However, the implementation faces technical challenges, particularly around mixed content blocking and the complexity of determining what constitutes a local network in modern enterprise environments.
Address Space Definitions:
- Public: Accessible to anyone on the internet
- Local: Private IP addresses accessible only to local network members (RFC1918)
- Localhost: Accessible only to the device itself (127.0.0.1, ::1)
Community Concerns and Enterprise Impact
The proposal has sparked significant debate about its potential impact on existing workflows. Many enterprise applications rely on public websites that can communicate with internal network resources. Some users worry about the effectiveness of permission prompts, noting that most people tend to click allow without fully understanding the implications.
Windows UAC has shown quite definitively that users will always click through any modal in their way without thought or comprehension.
There are also technical concerns about how this would work with IPv6 networks, where the distinction between local and public addresses is less clear-cut. Large enterprises often use private IP ranges for internal services that span multiple locations, complicating the definition of what constitutes a local network.
Legitimate Use Cases Still Supported
The proposal isn't designed to break legitimate functionality. Common use cases like OAuth flows that redirect to localhost, password manager integrations, and device setup workflows would still work, though they might require explicit user permission. The system would also allow manufacturers to continue using public websites to help users configure local devices, as long as users consent to the connection.
Local network browsing - like accessing your router's admin panel directly - wouldn't be affected since these don't involve cross-origin requests from external websites.
Requests Requiring Permission:
- Public → Local network requests
- Public → Localhost requests
- Local → Localhost requests
- Note: Local → Local requests would NOT require permission
Looking Forward
This proposal represents a significant shift toward user-controlled security in web browsers. While it may cause some initial friction for certain applications, it addresses a genuine security concern that has existed since the early days of the web. The challenge will be implementing it in a way that provides meaningful security benefits without creating excessive user frustration or breaking legitimate use cases.
The proposal is still in early stages and hasn't been approved for implementation in Chrome. The team is actively seeking feedback from developers and security experts to refine the approach before any potential rollout.
Reference: Explainer for Local Network Access